Road salting influences concrete and the surface layer for example on concrete bridges must be renewed after a number of years before the road salt has reached the reinforcement. The maintenance costs will be high if the salt already has had an effect on the reinforcement. Therefore, one wants to remove the surface layer and free the uppermost layer of reinforcement before the reinforcement has been influenced and then replace it with a new surface layer. Machines for such concrete removal are known from SE-451742-B, U.S. Pat. No. 5,361,993-A and SE 508821-C.
U.S. Pat. No. 5,361,993-A shows and describes a machine that is to be used in the way described above. The elongated nozzle holder is carried by a trolley that rolls on a guide. When the trolley reaches its end position, it remains there and the entire machine is stepped forwards so that the guide for the trolley is moved forwards. The trolley is still not moving while the nozzle holder is swung in order to provide an attack angle for the subsequent sweep. When the holder with its nozzle has reached its predefined angle, the trolley begins its movement. The nozzle moves with the same speed during its swinging movement as during the movement of the trolley.